Determination of 27 bovine plasma amino acids and metabolites using zwitterionic-hydrophilic interaction liquid chromatography coupled with isotope dilution electrospray ionization triple quadrupole liquid chromatography-mass spectrometry and the effect of deproteinization timing

Abstract

Graphical Abstract Summary This study evaluated and validated a zwitterionic-hydrophilic interaction liquid chromatography (Z-HILIC) and isotope dilution electrospray ionization triple quadrupole liquid chromatography-mass spectrometry method for analyzing amino acids (AA) and their derivatives in bovine plasma. The method demonstrated good quantitation results for linearity, precision, accuracy, and stability for most analytes, and the measured concentrations were consistent with published values. However, accurate recovery of cystine requires immediate deproteinization upon collection, and hydroxyproline was found to be unstable after a one-month freeze-thaw cycle. Overall, the method shows promise as a low-cost and efficient means of routinely analyzing plasma metabolites.